Vietnam coped with the problem of gypsum waste
DAP Joint-Stock Company (Vietnam), which for many years has been subjected to public criticism for environmental pollution, has found a solution to the problem with a large amount of toxic gypsum waste from its production. From now on, all the company's gypsum waste resulting from the production of phosphorous fertilizers will be processed into gypsum additives to cement.
According to experts, all types of industrial waste are more or less harmful to people and the environment. In this case, the damage is caused by the acid residue (phosphoric acid) that gets from the gypsum into the environment. During the normal processing of gypsum waste, the acid residue is not completely eliminated. DAP, in the course of its activities since 2009, has produced 2,000,000 tons of gypsum waste, which is still stored in the temporary landfill of the enterprise, seriously reducing the environmental indicators of the area. In order to prevent contamination, the landfill is covered with clay and stone mounds, as well as a layer of plastic film to prevent water from leaking out. A reservoir was also installed to collect acid from the waste and pump it back to the plant for use. The report for September 30, 2014 showed that wastewater contamination in the area of the plant is within the limits of the norm established in Vietnam.
Now gypsum waste, after several cycles of the described treatment, will be checked for compliance with the permissible pH level and transferred to a gypsum storage facility with an area of 40 hectares, from where it will be supplied for the production of cement additives. Production will be carried out by Dinh Vu Gypsum JSC, a company established in 2010 that successfully processes gypsum waste. At the moment, a quarter of the production lines with a capacity of 150,000 tons per year each have already been stopped.
As a result of the trial run of the plant, 10,000 tons of artificial gypsum were produced, which were already delivered to the cement plants of the partner DAP, which highly appreciated the quality of raw materials. In the future, it is planned to cooperate with the largest production facility in the country — the Vietnam Cement Corporation (Vicem). The companies have already signed an agreement under which Vicem will be responsible for the continuous consumption of the cement additive.
The only problem is that the Vietnamese public is not reassured by this solution to the problem: the use of recycled industrial waste in housing construction also raises many questions and concerns.
Source: http://english.vietnamnet.vn/